HyperChannels, also known as H-Channels and referred to elsewhere herein as "extended channels", are channels formed by combining smaller channels to obtain increased bandwidths [refer to: CCITT Red Book, Vol. III, Fascicle III.5, "Integrated Services Digital Network (ISDN), Recommendations of the Series I, Geneva 1985]. CCITT recommendations for HyperChannels in ISDN environments contemplate three types of HyperChannels, each having fixed bandwidth associated with national high speed communication links. The three types are; H0 type HyperChannels running at 384 Kbps, H11 HyperChannels running at 1.536 Mbps (or 4 times H0 speed), and H12 HyperChannels running at 1.920 Mbps (or 5 times H0 speed).
Above-mentioned CCITT recommendations define an environment for integral support of digitized voice and data communications, towards which national and supra-national telecommunication carrier systems appear to be evolving presently both in the United States and elsewhere. A basic simplex voice channel operates at 64 Kbps, and a full duplex voice channel operates at 128 Kbps (for sustaining voice communication at a quality level considered commercially acceptable). It is apparent that the operating speeds selected for HyperChannels as defined are predetermined multiples of the basic rates needed for single voice channels, either simplex or full duplex.
The present invention relates to a data link control device supporting dynamic formation and dissolution of HyperChannels, and having flexibility characteristics transcending limits imposed by the CCITT recommendations.